Many breathing masks have been developed for protecting humans from exposure to a variety of particulate and gaseous matter. However, prior masks have been unsuccessful in supplying sufficiently heated air to persons having respiratory and heart ailments to enable them to move about and work normally outside in cold weather without experiencing discomfort and pain. Typically, this discomfort and pain is experienced by persons having respiratory conditions such as asthma, bronchitis, chronic bronchitis, emphysema or coronary conditions such as angina pectoris, post myocardial infarction, congestive heart failure, coronary heart disease, post coronary bypass and the like.
Usually such persons experience sufficient pain and discomfort that they must cease exerting themselves and get into a warm environment and rest. Hence, their activity in cold weather must be severely curtailed and in some instances substantially eliminated.